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941.
Abstract: Isolates (47) of lactobacilli from 5 different productions of Melichloro cheese were examined for potential use as adjunct cultures. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) of whole‐cell proteins classified 29 isolates as L. paraplantarum and 18 as L. paracasei subsp. paracasei. Randomly amplified polymorphic DNA‐polymerase chain reaction (RAPD‐PCR) analysis differentiated the L. paraplantarum and L. paracasei subsp. paracasei isolates at strain level and both, RAPD analysis and whole‐cell protein profiling provided useful information about the diversity of nonstarter lactic acid bacteria (NSLAB) in the different cheese productions. The isolates were slow acidifiers and about 70% of them degraded, preferentially αs‐casein. The amounts of amino acids accumulated in the milk increased with the incubation time. A similar enzyme profile was exhibited by strains of both species, except for α‐mannosidase and α‐fucosidase, which were not detected in the L. paracasei subsp. paracasei strains. All strains grew in the presence of bile at 0.3% and the majority was able to withstand pH 2.5 and pancreatin at 0.1%. Moreover, all strains reduced cholesterol in vitro, with higher removal ability recorded for strains of L. paraplantarum. A narrow spectrum of antibacterial activity was recorded for 88% of the strains. Selected isolates with appropriate technological and interesting in vitro intestinal challenges could be used as adjuncts and deserve further studies. Practical Application: Strains selected by this study could be used as adjuncts to make the Melichloro cheese. Their contribution to cheese flavor is then going to be studied to select the most appropriate. Of course these strains have to be also studied for their probiotic potential, to say that we have a probiotic food.  相似文献   
942.
Abstract: The decontamination efficacy of 6 chemical treatments for beef trimmings were evaluated against Escherichia coli O157:H7 and 6 non‐O157 Shiga toxin‐producing E. coli (nSTEC) serogroups. Rifampicin‐resistant 4‐strain mixtures of E. coli O157:H7 and nSTEC serogroups O26, O45, O103, O111, O121, and O145 were separately inoculated (3 to 4 log CFU/cm2) onto trimmings (10 × 5 × 1 cm; approximately 100 g) fabricated from beef chuck rolls, and were immersed for 30 s in solutions of acidified sodium chlorite (0.1%, pH 2.5), peroxyacetic acid (0.02%, pH 3.8), sodium metasilicate (4%, pH 12.5), Bromitize® Plus (0.0225% active bromine, pH 6.6), or AFTEC 3000 (pH 1.2), or for 5 s in SYNTRx 3300 (pH 1.0). Each antimicrobial was tested independently together with an untreated control. Results showed that all tested decontamination treatments were similarly effective against the 6 nSTEC serogroups as they were against E. coli O157:H7. Irrespective of pathogen inoculum, treatment of beef trimmings with acidified sodium chlorite, peroxyacetic acid, or sodium metasilicate effectively (P < 0.05) reduced initial pathogen counts (3.4 to 3.9 log CFU/cm2) by 0.7 to 1.0, 0.6 to 1.0, and 1.3 to 1.5 log CFU/cm2, respectively. Reductions of pathogen counts (3.1 to 3.2 log CFU/cm2) by Bromitize Plus, AFTEC 3000, and SYNTRx 3300 were 0.1 to 0.4 log CFU/cm2, depending on treatment. Findings of this study should be useful to regulatory authorities and the meat industry as they consider nSTEC contamination in beef trimmings. Practical Applications: Findings of this study should be useful to: (i) meat processors as they design and conduct studies to validate the efficacy of antimicrobial treatments to control pathogen contamination on fresh beef products; and (ii) regulatory agencies as they consider approaches for better control of the studied pathogens.  相似文献   
943.
The determination of tin in canned food became very important in the last few years since it gives information about the contamination process helping to increase canned food quality and safety. The present work describes the development of a method for the determination of tin in canned tomato paste by electrothermal atomic absorption spectrometry in order to investigate the influents of (1) the industrial sample pretreatment procedure of canned tomato paste and (2) the type of materials used in packaging, on the total concentration of tin in canned tomato paste samples. For method validation, precision (repeatability and reproducibility) and accuracy (by recovery tests) have been assessed as performance criteria. The calculated recoveries ranged between 87.9% and 91.9%. The calculated expanded uncertainties based on the EURACHEM/CITAC Guidelines achieved from three different concentration levels were also calculated. The obtained results indicated that the method is efficiently and properly implemented. The validated method was applied for tin concentration determination in canned tomato paste purchased from the local market. In all analyzed samples, tin concentrations levels were lower than the maximum permissible value recommended by the European Regulation.  相似文献   
944.
Xynomavro and Muscat Hamburg grapes were fermented spontaneously, producing red and white wine, respectively. The indigenous yeast flora, isolated at three phases of these fermentations, was studied. One hundred and ten strains were isolated, eighty-four of which were identified as Saccharomyces cerevisiae. Six of these strains were selected for their satisfactory oenological properties to be tested as starters in wine fermentations. The quality of the produced wines was evaluated after determination of their aromatic compounds and sensory analysis. S. cerevisiae strain BT4, as well as the AM4+BM3 combination, were considered the best as they produced wines characterized by fruity aromas and were highly accepted among panelists.  相似文献   
945.
This paper makes an analysis of all reported accidents and incidents in the Greek Petrochemical Industry for the period spanning from 1997 to 2003. The work performed is related to the analysis of important parameters of the incidents, their inclusion in a database adequately designed for the purposes of this analysis and an importance assessment of this reporting scheme. Indeed, various stakeholders have highlighted the importance of a reporting system for industrial accidents and incidents. The European Union has established for this purpose the Major Accident Reporting System (MARS) for the reporting of major accidents in the Member States. However, major accidents are not the only measure that can characterize the safety status of an establishment; neither are the former the only events from which important lessons can be learned. Near misses, industrial incidents without major consequences, as well as occupational accidents could equally supply with important findings the interested analyst, while statistical analysis of these incidents could give significant insight in the understanding and the prevention of similar incidents or major accidents in the future. This analysis could be more significant, if each industrial sector was separately analyzed, as the authors do for the petrochemical sector in the present article.  相似文献   
946.
Tsakiris SI  Uzunoglu NK 《Applied optics》2006,45(34):8764-8771
A fiber-optic-based coupled waveguide transmission medium is proposed to distribute secret keys in a single-photon polarization-based quantum cryptography setup. Polarization maintenance properties and coupling phenomena of the transmission medium are exploited to achieve accuracy and security of the transferred key. Elliptic fibers and fiber couplers are used to prepare the transmitted photons at the sender as well as analyze them at the receiver. The uniqueness of the setup stands on the exclusive use of fiber-optic components, enabling its construction on a single fiber line.  相似文献   
947.
Kinetic data on thermal destruction of spoilage and quality factors coupled with the temperature history of a product during a heat sterilization cycle are the basic information needed for the evaluation and the design of thermal processes through a physical‐mathematical approach. A critical review on the available physical‐mathematical procedures used for thermal process calculations of in‐container processed foods is presented. The origin and the limitations of each method are discussed. The equations associated with each method, for internal product temperature predictions, are explicitly given. The relative performance of selected methods under identical processing conditions is illustrated. Several problems associated with thermal process calculations are discussed.  相似文献   
948.
The objective of this study was to investigate the possibility of using waste paper recovered from old corrugated containers (OCC) as substitute for wood particles in the production of particleboards. Three proportions of wood chips: waste paper flakes (100:0, 70:30, 50:50) were used in the production of one-layer and the core of three-layer experimental particleboards. Various adhesive systems were applied as binders: a UF resin (E1 grade), a PMDI resin and three UF:PMDI combinations: (6:2, 5:3 and 4:4). The evaluation of the board’s mechanical and hygroscopic properties showed the following results: Replacing woods chips with waste OCC paper adversely affected the board’s properties. The participation of waste paper in the core layer resulted in decreased differentiation between surface and core density of the boards. Partial substitution of UF resin by PMDI in amounts of 2–4?% significantly improved the properties of boards containing 30 and 50?% waste paper. An increase in board density resulted in a corresponding improvement in mechanical properties. In terms of mechanical properties, three-layer UF boards containing 30?% and PMDI bonded boards containing 30 and 50?% waste paper in the core layer complied with the requirements of European Standard EN312 for board types P1, P2 and P4 for use in interior applications.  相似文献   
949.
In this work two systems consisting on polyaniline (Pani) doped with simple and small gap C60 fullerenes have been prepared and characterized. Composites with different doping amounts of 1,2,4 and 8 wt% have been analyzed in order to evaluate their structure together with their optical and electrical properties and the effect of fullerene type and amount on them. The shift and change of shape in Fourier transform infrared spectroscopy (FTIR) bands and solid 13C NMR spectroscopy signals showed the presence of interactions between matrix and fullerenes by electron density transfer among them. Optical properties have also been analyzed in terms of ultraviolet (UV) spectroscopy. The blue shift of several bands confirmed the charge transfer. Obtained structures have been analyzed by optical microscopy (OM) showing the different way in which both types of fullerenes have been incorporated into the polymer chains. Finally, conductivity has been measured by the four probe technique, relating obtained values with the structure of the composite and the different degree of crystallinity of simple and small gap fullerenes.  相似文献   
950.
Advances in molecular technologies over the past few decades, such as high-throughput DNA marker genotyping, have provided more powerful plant breeding approaches, including marker-assisted selection and genomic selection. At the same time, massive investments in plant genetics and genomics, led by whole genome sequencing, have led to greater knowledge of genes and genetic pathways across plant genomes. However, there remains a gap between approaches focused on forward genetics, which start with a phenotype to map a mutant locus or QTL with the goal of cloning the causal gene, and approaches using reverse genetics, which start with large-scale sequence data and work back to the gene function. The recent establishment of efficient CRISPR-Cas-based gene editing promises to bridge this gap and provide a rapid method to functionally validate genes and alleles identified through studies of natural variation. CRISPR-Cas techniques can be used to knock out single or multiple genes, precisely modify genes through base and prime editing, and replace alleles. Moreover, technologies such as protoplast isolation, in planta transformation, and the use of developmental regulatory genes promise to enable high-throughput gene editing to accelerate crop improvement.  相似文献   
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